大鼠结肠慢性炎性刺激诱导腰骶髓和延髓Fos的表达及其意义  

Fos expression in rat lumbarsacral spinal cord and medulla oblongata induced by chronic colonic inflammation

作　　者：孙怡宁[1] 罗金燕[1] 

机构地区：[1]西安交通大学第二医院消化科,710004

出　　处：《中华消化杂志》2004年第7期403-406,共4页Chinese Journal of Digestion

摘　　要：目的　探讨实验性大鼠结肠慢性炎性刺激诱导腰骶髓和延髓中Fos的表达及其意义。方法　成年雄性SD大鼠 ,实验组 (n =1 6 )予三硝基苯磺酸 (TNBS)灌肠诱导结肠炎 ,实验对照组 (n =8)予生理盐水灌肠 ,空白对照组 (n =2 )不予任何刺激 ;分别在灌肠后 3、7、1 4和 2 8d ,采用免疫组化法观察实验组大鼠腰骶髓和延髓中Fos阳性神经元的数量和分布 ,并与对照组进行比较。结果　TNBS灌肠诱导Fos表达多数分布在脊髓背角深层 (Ⅲ～Ⅳ和Ⅴ～Ⅵ层 )和由孤束核、腹外侧区及网状结构形成的延髓内脏带中。TNBS灌肠后 3d ,脊髓和延髓中Fos表达无明显增多。灌肠后 7和 1 4d ,脊髓和延髓中Fos表达明显多于实验对照组 (P <0 .0 5 )。灌肠后 2 8d ,延髓中Fos表达下降 ,与对照组无明显差异 ,部分大鼠脊髓中Fos阳性神经元数 (5 4 .1± 1 6 .3)仍明显多于对照组 (1 2 .2± 2 .6 ,P <0 .0 5 )。结论　脊髓Fos阳性神经元可能在结肠慢性炎性刺激引起的内脏高敏感性中起作用 ,而延髓可能不是内脏高敏感性形成的主要部位。Objective The aim of this study was to investigate Fos expression in rat lumbarsacral spinal cord and medulla oblongata induced by chronic colonic inflammation. Methods Twenty six male Sprague Dawley rats were divided into three groups: group 1, colonic inflammation was induced in sixteen rats by intraluminal instillation of trinitrobenzenesulfonic acid (TNBS); group 2, saline was instilled intraluminally in eight rats; group 3, no stimulation was given in 2 rats. After 3, 7, 14 and 28 days of instillation, lumbarsacral spinal cord and medulla oblongata were removed and processed for Fos immunohistochemical staining. Results Fos neurons induced by TNBS instillation were mainly distributed in deep laminae (laminae Ⅲ Ⅳ,Ⅴ Ⅵ) in spinal dorsal horn and in medullary visceral zone in medulla oblongata. The number of Fos cells in the spinal cord and medullary visceral zone was significantly higher in rats after 7 and 14 day of TNBS instillation compared with that of controls. After 28 days of TNBS instillation, the number of Fos neurons in the medullary visceral zone decreased and became comparable to that of control group. However, the number of Fos cells (54.1±16.3) in the spinal cord in some rats was still significantly higher than that of controls (12.2 ±2.6, P < 0.05 ). Conclusions Increased expression of Fos in the spinal dorsal horn may render the neurons susceptible to subsequent stimuli. Medulla oblongata may be a less important structure than the spinal cord in inducing visceral hypersensitivity after chronic colonic inflammation.

关 键 词：大鼠 结肠 慢性炎性刺激 腰骶髓 延髓Fos 基因表达 肠易激综合征 延髓内脏带 

分 类 号：R574[医药卫生—消化系统]